Re: [PATCH v3 3/4] rtc: rk8xx: Add base support for the RK808 PMIC RTC

+Elaine,

Please help to review this patch.

Thanks,

- Kever

On 2020/4/29 上午12:14, sunil@amarulasolutions.com wrote:

From: Suniel Mahesh sunil@amarulasolutions.com

Rockchip RK808 PMIC provides an integrated RTC module. It is commonly used with Rockchip SoCs. Add basic support to access date and time.

Signed-off-by: Suniel Mahesh sunil@amarulasolutions.com

Changes for v3:

• no changes

Changes for v2:

• moved corresponding configs which enable rtc into a seperate patch.
• changed subject line.

Note:

1. The RK808 PMIC RTC has a hardware bug. It counts 31 days

for november month and the weeks register counts 0 - 7.

2. This driver does a temporary fix, where as in if date is Nov 31,

then it resets the date to Dec 1(this happens only if date cmd is queried from u-boot command line/script). Similarly for the weeks register, 0(sun)

• 6(sat). If 7 is encountered then it is reset to zero.

3. u-boot generally loads linux/other binary. Linux has a full fledged

driver implemented along with a workaround. https://lkml.org/lkml/2015/12/2/1202

4. Is this change acceptable ? please comment

---

drivers/rtc/Kconfig | 8 +++ drivers/rtc/Makefile | 1 + drivers/rtc/rk808-rtc.c | 165 ++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 174 insertions(+) create mode 100644 drivers/rtc/rk808-rtc.c

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 59e2fc4..a754d1b 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -75,6 +75,14 @@ config RTC_ISL1208 This driver supports reading and writing the RTC/calendar and detects total power failures.

+config RTC_RK808

• bool "Enable Rockchip RK8XX RTC driver"

•    depends on DM_RTC && PMIC_RK8XX
  

• default y
• help

•  Basic support for Rockchip RK808 PMIC Real Time Clock devices for
  

•  time and date.
  

• config RTC_RV3029 bool "Enable RV3029 driver" depends on DM_RTC

diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 12eb449..63e2c34 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -44,6 +44,7 @@ obj-$(CONFIG_RTC_PCF8563) += pcf8563.o obj-$(CONFIG_RTC_PCF2127) += pcf2127.o obj-$(CONFIG_RTC_PL031) += pl031.o obj-$(CONFIG_RTC_PT7C4338) += pt7c4338.o +obj-$(CONFIG_RTC_RK808) += rk808-rtc.o obj-$(CONFIG_RTC_RS5C372A) += rs5c372.o obj-$(CONFIG_RTC_RV3029) += rv3029.o obj-$(CONFIG_RTC_RV8803) += rv8803.o diff --git a/drivers/rtc/rk808-rtc.c b/drivers/rtc/rk808-rtc.c new file mode 100644 index 0000000..b63cced --- /dev/null +++ b/drivers/rtc/rk808-rtc.c @@ -0,0 +1,165 @@ +// SPDX-License-Identifier: GPL-2.0+ +/*

• • RTC driver for Rockchip RK808 PMIC.
• • Copyright (C) 2020 Amarula Solutions(India).
• • Suniel Mahesh sunil@amarulasolutions.com
• • Based on code from Linux kernel:
• • Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
• • Author: Chris Zhong zyw@rock-chips.com
• • Author: Zhang Qing zhangqing@rock-chips.com
• • Date & Time support (no alarms and interrupts)
• */

+#include <command.h> +#include <common.h> +#include <dm.h> +#include <i2c.h> +#include <rtc.h> +#include <power/rk8xx_pmic.h> +#include <power/pmic.h>

+/* RTC_CTRL_REG bitfields */ +#define BIT_RTC_CTRL_REG_STOP_RTC_M BIT(0)

+/* RK808 has a shadowed register for saving a "frozen" RTC time.

• • When user setting "GET_TIME" to 1, the time will save in this shadowed
• • register. If set "READSEL" to 1, user read rtc time register, actually
• • get the time of that moment. If we need the real time, clr this bit.
• */

+#define BIT_RTC_CTRL_REG_RTC_GET_TIME BIT(6) +#define BIT_RTC_CTRL_REG_RTC_READSEL_M BIT(7) +#define RTC_STATUS_MASK 0xFE

+#define SECONDS_REG_MSK 0x7F +#define MINUTES_REG_MAK 0x7F +#define HOURS_REG_MSK 0x3F +#define DAYS_REG_MSK 0x3F +#define MONTHS_REG_MSK 0x1F +#define YEARS_REG_MSK 0xFF +#define WEEKS_REG_MSK 0x7

+/* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */

+#define NUM_TIME_REGS (REG_WEEKS - REG_SECONDS + 1)

+static int rk808_rtc_set(struct udevice *dev, const struct rtc_time *tm) +{

• u8 rtc_data[NUM_TIME_REGS];
• debug("RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",

• 	tm->tm_year, tm->tm_mon, tm->tm_mday,
  

• 	tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
  

• rtc_data[0] = bin2bcd(tm->tm_sec);
• rtc_data[1] = bin2bcd(tm->tm_min);
• rtc_data[2] = bin2bcd(tm->tm_hour);
• rtc_data[3] = bin2bcd(tm->tm_mday);
• rtc_data[4] = bin2bcd(tm->tm_mon);
• rtc_data[5] = bin2bcd(tm->tm_year - 2000);
• rtc_data[6] = bin2bcd(tm->tm_wday);

+/* Stop RTC while updating the RTC registers */

• pmic_clrsetbits(dev->parent, REG_RTC_CTRL, 0,

• 				BIT_RTC_CTRL_REG_STOP_RTC_M);
  

• pmic_write(dev->parent, REG_SECONDS, rtc_data, NUM_TIME_REGS);

+/* Start RTC again */

• pmic_clrsetbits(dev->parent, REG_RTC_CTRL,

• 				BIT_RTC_CTRL_REG_STOP_RTC_M, 0);
  

• return 0;

+}

+static int rk808_rtc_get(struct udevice *dev, struct rtc_time *tm) +{

• u8 rtc_data[NUM_TIME_REGS];

+/* Force an update of the shadowed registers right now */

• pmic_clrsetbits(dev->parent, REG_RTC_CTRL, 0,

• 				BIT_RTC_CTRL_REG_RTC_GET_TIME);
  

+/*

• • After we set the GET_TIME bit, the rtc time can't be read
• • immediately. So we should wait up to 31.25 us, about one cycle of
• • 32khz. If we clear the GET_TIME bit here, the time of i2c transfer
• • certainly more than 31.25us: 16 * 2.5us at 400kHz bus frequency.
• */
• pmic_clrsetbits(dev->parent, REG_RTC_CTRL,

• 			BIT_RTC_CTRL_REG_RTC_GET_TIME, 0);
  

• pmic_read(dev->parent, REG_SECONDS, rtc_data, NUM_TIME_REGS);
• tm->tm_sec = bcd2bin(rtc_data[0] & SECONDS_REG_MSK);
• tm->tm_min = bcd2bin(rtc_data[1] & MINUTES_REG_MAK);
• tm->tm_hour = bcd2bin(rtc_data[2] & HOURS_REG_MSK);
• tm->tm_mday = bcd2bin(rtc_data[3] & DAYS_REG_MSK);
• tm->tm_mon = (bcd2bin(rtc_data[4] & MONTHS_REG_MSK));
• tm->tm_year = (bcd2bin(rtc_data[5] & YEARS_REG_MSK)) + 2000;
• tm->tm_wday = bcd2bin(rtc_data[6] & WEEKS_REG_MSK);

+/*

• • RK808 PMIC RTC h/w counts/has 31 days in november. This is corrected
• • when date cmd is invoked on prompt. checks for the current day and
• • if it is 31 November, then adjusts it to 1 December.
• • h/w also has weeks register which counts from 0 to 7(0(sun)-6(sat)).
• • 7 is an unknown state, reset it back to 0(sun).
• */
• if (tm->tm_mon == 11 && tm->tm_mday == 31) {

• debug("correcting Nov 31st to Dec 1st (HW bug)\n");
  

• tm->tm_mon += 1;
  

• tm->tm_mday = 1;
  

• if (tm->tm_wday == 7)
  

• 	tm->tm_wday = 0;
  

• rk808_rtc_set(dev, tm);
  

• }
• if (tm->tm_wday == 7) {

• tm->tm_wday = 0;
  

• rk808_rtc_set(dev, tm);
  

• }
• debug("RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",

• 	tm->tm_year, tm->tm_mon, tm->tm_mday,
  

• 	tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
  

• return 0;

+}

+static int rk808_rtc_reset(struct udevice *dev) +{ +/* Not needed */

• return 0;

+}

+static int rk808_rtc_init(struct udevice *dev) +{

• struct rtc_time tm;

+/* start rtc running by default, and use shadowed timer. */

• pmic_clrsetbits(dev->parent, REG_RTC_CTRL, 0,

• 			BIT_RTC_CTRL_REG_RTC_READSEL_M);
  

• pmic_reg_write(dev->parent, REG_RTC_STATUS, RTC_STATUS_MASK);

+/* set init time */

• rk808_rtc_get(dev, &tm);
• return 0;

+}

+static int rk808_rtc_probe(struct udevice *dev) +{

• rk808_rtc_init(dev);
• return 0;

+}

+static const struct rtc_ops rk808_rtc_ops = {

• .get = rk808_rtc_get,
• .set = rk808_rtc_set,
• .reset = rk808_rtc_reset,

+};

+U_BOOT_DRIVER(rk808_rtc) = {

• .name = "rk808_rtc",
• .id = UCLASS_RTC,
• .ops = &rk808_rtc_ops,
• .probe = rk808_rtc_probe,

+};